Three South Korean companies will plead guilty to criminal charges and pay $236 million for their role in a conspiracy to fix the price of fuel sold to U.S. military bases in South Korea, the Justice Department said on Wednesday.

SK Energy; GS Caltex, 50 percent owned by Chevron; and Hanjin Transportation agreed to pay $154 million in civil damages to the United States and $82 million in criminal fines, the department said.

The settlement was part of a larger investigation involving other companies, the head of the Justice Department's antitrust division, Assistant Attorney General Makan Delrahim, told reporters.

The three "and other co-conspirators rigged bids and fixed prices for fuel supply contracts issued by the U.S. military in this strategically critical region for over a decade," Delrahim said.

The conspiracy began around March 2005 and continued until 2016, with South Korean petroleum and refinery companies and their agents working to suppress competition during the bidding process for U.S. military fuel contracts, the department said.

"As a result of the anti-competitive agreement, the U.S. Department of Defense paid substantially more for fuel supply services than it would have absent the collusion," Delrahim
said.

SK Energy and GS Caltex could not immediately be reached for comment.

Hanjin representative Seung Bae Lee said the company was "committed to complying with the antitrust and competition laws and values its decades-long relationship with the U.S. military."

Between criminal fines and other payments, SK Energy is to pay $124.5 million, GS Caltex will pay $104.2 million and Hanjin will pay $7.6 million, according to Justice Department data.

The payments made by the companies "exceeds the amount of the individual overcharge," the department said.